Spindle-lock for micrometer-gages, &amp;c.



110.8%,594. v 4 'PATENTEDDEG.5,1905.

' L. s. STARRETT.

- I SPINDLE LO GK FOR MICROMETER GAGES, 6w.

APPLICATION FILED maze, 1905.

7 tween its tubular end portions an annular' UNITED STATES 'LAROY S.STARRETT, ATHOL, MASSACHUSETTS, ASSIGNOR TO L. S. STARRETT COMPANY, OFATHOL,

OF MASSACHUSETTS.

PATENT OFFICE.

MASSACHUSETTS, A. CORPORATION SPINDLE-LOCK FOR MIC-ROMETER-GAGES.-&o.

Specification of Letters Patent.

Patented. Dec. 5, 1905.

Application filed March 23, 1905. Serial no. 251,691.

To all whom it mag/concern.-

Be it known that I, LAROY S. STARRETT, of

Athol, in the county of Worcester and State of Massachusetts,haveiinvented certain new anduseful Improvements in Spindle-Locks forMicrometenGages, &c., of which the fol- "lowing is a specification.

The object of this invention is to provide at small cost a simple andmost efiicient device for locking a rotatable shaft or spindle in itsbearing, so as by a very slight rotary movement to hold the shaft orspindle in any given adjusted position.

My especial purpose is, as herein illustrated, to perfect the ordinarymicrometer-caliper by furnishing it with my improved locking device.

My improvement consists in bushing firmly secured in the tool-head orbearing portion of a micrometer-body surrounding its rotatable spindleand having bespring-tongue integral with and nearly severed from saidend portions in parallel transverse planes and nearly-or quite severedat one end in a longitudinal or axial plane and weakened to permit aslight yielding or spring action at that end of the tongue, said tonguehaving near such longitudinal plane of severance a flat-bottomedperipheral recess deepest at its radial inner end and decreasing thenceoutwardly, the plane of its bottom being preferably the half-chord of ashort are and terminating abruptly, in combination with a minute bar orroller located longitudinally in said recess with its ends adjacent tothe inner walls of the end portions of said bushing and with anactuating-ring fitting rotatably into a transverse slot in the tool-headand loosely around said annular tongue and the rollerin' closed in itsrecess.

In thedrawings, Figure 1 is a side elevation of a micrometer-caliperprovided with my improvement. Fig. 2 is an enlarged longitudinal sectionthrough the tool-head and locking device. Figs. 3 and 4 are transversesections taken, respectively, on lines 3 and4, Fig. 2. Fig. 5 is a sideview, and Fig. 6 a distorted perspective, of the bushing detached.

. In Fig. 1, 10 represents the tool-head at one end of its curved body,11 the fixed cylindrical shell projecting from the head, and 12 therotatable sleeve surrounding said shell, both bea cylindrical ingaccurately graduated in a manner well known in instruments of thisclass. The spindle 13 is secured at its inner end for rotation with saidsleeve and has a threaded engagement within shell 11 of a pitchcorresponding to the graduations on said shell. 1

- In applying my improved locking device to a rotatable shaft orcaliper-spindle I form through the bearing portion or head 10 atransverse slot 14 perpendicular to the spindleaxis. ring 15, snuglyfitting between the slot-walls and extending radiallyslightly beyondtheperiphery of the bearing, or head, and I introduce axially into saidbearing or head and through ring 15 a cylindrical bushing 16 of peculiarconstruction and secure it firmly within head 10, said ring beingrotatable in. slot 14 around such bushing. Between; the end portions ofbushing-16 and integral with Ithen place within said slot a milled.

it I form an annular spring-tongue 17 in the plane of but slightlynarrower than ring 15 by sawing two deep parallel transverse slots 18,as best shown in Figs. 5 and 6, such slots nearly severing the bushing,as in Fig. 4:, which is a section inthe plane of one of these slots.Adeep longitudinal saw-cut, slot, or groove 19 at one end of slots 18and a peripheral recess 20 adjacent thereto so weaken the ring-shapedtongue that at that point it may be pressed slightly inward into bindingcontact with the inclosed spindle, so as to prevent its rotation. Therecess 20 (best shown in Fig. 6) has a fiat bottom and radial inner endwall extending thefull width of the tongue, said bottom preferablyforming the half-chord of a short are and said recess diminishing indepth from such end wall and disappearing near slot 19.

,cess with a wedging action, which springs that part of the tongueinwardly and locks the spindle firmly. A similarly-limited-reversemovement of ring 15 instantly releases the grip upon the spindle.

I claim as my invention 1. The described locking device for a rotatableshaft or spindle, comprising abearing or tool-head formed with a deeptransverse slot, a cylindrical bushing inserted axially and fixed inposition in such bearing or head, bored to fit the inclosed shaft orspindle, and having between its rigid end portions and in the plane ofsaid slot an annular springtongue integral with but nearlysevered fromsuch end portions and formed with a peripheral recess deepest at itsabrupt inner end, decreasing in depth outwardly therefrom in a planeflat bottom, in combination with a movable clampingpiece locatedlongitudinally in said recess, its diameter being equal to the greatestdepth thereof, and with an actuating-ring fitting rotatably in thetool-head slot and around the recessed tongue and inclosed piecesubstantially as set forth.

2. In a micrometer-gage the tool frame or head, the rotatable spindleand micrometer mechanism, a deep transverse slot in the toolripheralrecess, deepest at its radial inner end and decreasing thence outwardly,its fiat bottom forming the half-chord of a short are, and a roller of adiameter equal only to the greatest depth of such recess held movablytherein and operated by said actuating-ring, for the purpose set forth.

In testimony whereof I have aflixed my signature in presence of twowitnesses.

LAROY S. STARRETT.

Witnesses:

FLORENCE E. Boron, FRANK E. TING.

